造纸废水的电离辐射预处理工艺研究

造纸废水是我国污染最为严重的难降解工业废水之一,研究了电离辐射处理造纸废水的可行性,探讨了混凝、辐照以及混凝-辐照组合工艺对废纸造纸废水的COD、BOD<,5>、吸光度、DOC以及有机物相对分子质量分布的影响.实验发现,造纸废水的COD主要是由相对分子质量<3 000的有机物构成,相对分子质量为1 000～3 000的...

Pretreatment of Paper Mill Effluent by a Combined Process of Coagulation and Ionizing Radiation

Paper mill effluent is one of the most refractory industrial wastewater in China. The feasibility of treating paper mill effluent by ionizing radiation was studied experimentally. This article investigated the effect of coagulation, ionizing radiation, and the combined process of coagulation and ionizing radiation on COD, BOD₅, absorbance DOC and molecular weight distribution of soluble organic compounds in paper mill effluent. It was found that COD of wastewater consist of organic compounds (M_r<3000). The organic compounds (1000<M_r<3000) made 44.5% contribution to COD and M_r<1000 41.6%. Coagulation technology can effectively remove the organic compounds (M_r>3000) with its removal rate of 44.7%. But the organic compounds (M_r<3000) was only removed by 20.0%. Coagulation can also reduce the absorbance of wastewater significantly and improve the efficiency of ionizing irradiation for the degradation efficiency of organic compounds (M_r<3000). The macromolecule organic compounds were coagulated so as to make UV wavelength decreased after irradiation. The absorption peak (<250 nm) was decreased by irradiation, meanwhile the absorption peak (>250 nm) increased. However, there are both degradation and polymerization effects for organic compounds in paper mill effluent by radiation technology. The polymerization shows greater effect compared with the degradation for organic compounds (M_r>3000), while the effect is opposite for organic compounds (M_r<3000). Combined process of coagulation and ionizing radiation not only effectively remove organic compounds (M_r>3000) in paper mill effluent, but also increases the biodegradability of organic compounds (M_r<3000). Therefore, the combined process of coagulation and ionizing radiation possesses highly effective applicability for paper mill effluent.